On 10/6/2011 8:42 PM, Tony Hwang wrote:


Sam Takoy wrote:
Hi,

If I buy a generator that's too big for average use for my house - for
example, I really need a 3500 but get a 7000 instead - and most of the
time don't draw more than 3500, will I be wasting have the gas or are
the generators smart enough these days to burn only as much gas as
needed?

Thanks,

Sam
Hi,
If cost is not a big concern, I'd always take over sized one than just
right or undersized one in anything.


My Generac 7KW was the smallest standby generator sold in 2006, and I
bought it since it had more than enough power to carry my basic home
needs (furnace, refrigerator, sump pump, most lighting, computers, TVs,
garage door opener, microwave, etc.)

The idling consumption of gas is about 50% lower than the idling
consumption on the next larger model, and thus a partially loaded 7KW
generator consumes considerably less fuel than the same load on a 10 or
15KW unit. This results in a simpler installer (smaller diameter gas
line and no need to upgrade the gas meter) as well as lower operating
costs as well as lower first installation cost by at least $1500 saved
up front.

The 7KW generator is smaller, quieter, and cheaper, and made the most
sense to me. I have never regretted using a minimalistic approach here.

To be fair, the negative side is that I cannot supply enough power to
run my home central a/c, my electric ovens, or my electric clothes
dryer. And I suppose that my single cylinder engine will not last as
long as the 2 cylinder engines used in the more expensive models.

Generac, Kohler, and others have deliberate;y made the transfer switch /
breaker panel for the cheaper models offer fewer circuits. This limits
the number of home devices which can be powered, and some people buy the
larger generators so as to have more powered circuits supported. Careful
rearrangement of branch circuits in your home can overcome some of this
constraint.

I therefore would vote for having LESS rather than more in a standby
generator, and would certainly buy another smaller unit like the 7KW if
I was doing it over again.